Vehicle seats are made from a variety of different materials and are configured in countless shapes and sizes to accommodate the particular requirements of the vehicle in which they are used. A common seating material used in passenger and commercial vehicles is leather—either real leather made from the tanned hide of an animal, or synthetic leather, which emulates the appearance and feel of real leather. Seat cushions may be made up of a top surface of leather and an undersurface of a stiff backing material attached to a backside of the leather, with foam padding inserted between the two layers.
Although the stiff backing material may facilitate manufacturing and assembly processes, using such a material on a vehicle seat cushion has inherent drawbacks. For example, the stiff backing material does not stretch in the same way that the leather upper material does. Thus, when a seat cushion having a stiff backing is attached to side bolsters, the bolsters are apt to deform as a result of the force applied by the backing material when a person occupies the seat. It would be more desirable to have a seat cushion with increased elasticity so that the cushion would accept more of the deformation, thereby leaving the bolsters and other seat structures intact.
Another problem with some seat cushions is that they employ a thick seat trim cover panel, for example, a panel made of three layers—e.g., an upper material, a foam wadding material, and a backing material. Such a cushion may not lie flat as it is attached to the frame and other seat structures. The process of attaching the backing material to the leather material with a foam padding in between may result in a cushion having a backside surface that is not planar. In such a case, attachment devices, such as wire, straps, etc. must be utilized to not only attach the seat cushion to the seat structure, but also to pull down any edges or corners, and the center of the trim cover panel, so that the cushion remains flat.
Another reason that a cushion may be difficult to attach to a seat structure is because many cushions are manufactured with a generally rectangular perimeter. This facilitates the manufacturing processes, by making material pieces that are easy to cut and assemble. For example, if the entire seat cushion has a generally rectangular perimeter, the piece or pieces of foam padding can also have a generally rectangular shape, thereby making it easier to insert the foam padding into pre-sewn pockets formed by the leather and the stiff backing material. Despite the ease of manufacturing, the rectangular shape may not be desirable from a form and fit perspective.
It would therefore be desirable to provide a seat cushion assembly and method of manufacture that overcomes some or all of the aforementioned problems, by providing a seat cushion that reduces the deformation side bolsters and other attached seat components, and presents a more planar surface for easier attachment to a seat structure.